1. Field of the Invention
The present invention relates to a weighing apparatus that can be used to weigh many different types of loads but which is particularly well adapted to weigh a load carried in a container such as a hopper or tote bin. The weighing apparatus may, for example, have a central hole which accommodates a depending hopper chute. Alternatively, the apparatus may be adapted to have an upper platform for supporting a load at any location thereon.
For optimum versatility, weighing apparatus of the type described above should have a high weighing capacity. Moreover, for convenience of use, they can be made portable, not requiring special permanent installations.
It is also desirable to provide a weighing apparatus which can be readily adapted to various applications which require different weighing surface dimensions.
2. Description of the Prior Art
Many types of weighing apparatus are known. For example, U.S. Pat. No. 3,933,212 (Bradley et al.), assigned to the assignee of the present invention, discloses a high capacity platform weighing apparatus having an extremely low profile to permit the weighing surface to be easily mounted by a loaded truck. Furthermore, this apparatus offers little obstruction to the area in which it is installed. The weighing apparatus includes an underlying frame structure having a superposed platform structure. A plurality of load cells are mounted between the two structures at spaced locations. The attachment of the cells to these structures permits easy installation, disassembly, and maintenance. A ramp in the form of a truncated pyramid surrounds the platform structure so that the weighing surface can be mounted from any side. The platform and frame structures are constrained to move relative to each other only in the vertical direction by a bracing arrangement.
The platform weighing apparatus disclosed in the Bradley et al. Patent has many features which make it superior to similar apparatus. However, the platform and frame structure is of fixed size. Therefore, a given apparatus constructed in accordance with the invention cannot be readily adapted to weighing applications requiring a platform surface of different size.
Other weighing devices are disclosed in U.S. Pat. No. 3,299,976 (Boadle et al.), British patent specification No. 1,060,838 and French Pat. No. 1,508,241.